Crossword Puzzle 'Keystone' character

Clue: 'Keystone' character

Super Bowl to be played in the year 3968, at the current rate (MMII with 4 letters)
39th VP (AGNEW with 5 letters)
39th vice president (AGNEW with 5 letters)
39th Veep (AGNEW with 5 letters)
39th of 50 (NORTHDAKOTA with 11 letters)
39th V.P. (AGNEW with 5 letters)
America's 39th President (CARTER with 6 letters)
Keystone character (KOP with 3 letters)
"Keystone" character (KOP with 3 letters)
Favorite Hall of Famer of the 39th U.S. president? (GARYCARTER with 10 letters)